Heating-furnace.



Patented Apr. I6, 190|. A. LAuGHLm.

HEATING FURIMCE.

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Y mums Farms co.. Puornurno.. wsHmnTcn n n niirnn drains ldarniur@ritieni ALEXANDER LAUGHLIN, OF SEWICKLEY, PENNSYLVANIA.

HEATIINGMFURNACE.

SPECIFICATION formingpart of Letters Patent No.. 672,381, dated April16, 1901.

Application led DetembernZ, 1898. Serial No. 698,056. (No model.)

T0 L7/Z whom, t nwty concern:

Be itknown that I, ALEXANDER LAUGHLIN, a citizen of the United States,residing at Sewickley, in the county of Allegheny and State ofPennsylvania, have invented or discovered a certain new and usefulImprovement in I'IeatingFurn aces, of which improvement the following isa specification.

It has heretofore been the general practice to construct continuousheating-furnaces with a roof approximately parallel from end to end withthe bed of the furnace. This constructionhas been modified in some casesby giving the roof a gradual upward slope from the charging to thedrawing or discharging end of the furnace, as shown in dotted lines inFig ures 4 to 6. Both of these forms of furnaces are objectionable,forthe reason that the heat and products of combustion have a free andunobstructed iiow from the drawing ordischarging end of the furnace backto the outlet-flues at the charging end. It follows by reason of thisfree fiow that when sufficient heat is produced to raise the billets atthe drawing or discharging end to the proper temperatu re approximatelythe same heating effect will extend nearly to the charging end of thefurnace, so that the billets are raised and maintained at a hightemperature for a considerable time before reaching the drawing ordischarging end of the furnace. This high and `maintained preheatingresults in a seriously high loss of metal by oxidation and bleeding atthe billets.

The object of the present invention is to so construct this class offurnaces that the billets will be subjected to maximum heating onlyshortly prior to the time they are drawn or discharged from the furnaceand will be gradually heated, but not to a temperature that will permitof material loss from the charging end up to the point where they willbe subjected to the maximum heating.

The invention is hereinafter more fully described and claimed.

In the accompanying drawings, forming a part of this specification, Fig.1 is a sectional plan view of a continuous heating-fu rnace of theautomatic-discharge type having my improvement applied thereto. Fig. 2is alongitudinal sectional elevation ofthe same. Fig. 2a is a transversesection on the line c on,

Fig. 2. Figs. 3 and 4 are views similar' to Figs. 1 and 2, showing myimprovement ap plied to furnaces having an automatic discharge throughthe bot-tom of the hearth. Figs. 5 and 6 are sectional plan andelevations showing my improvement applied to furnaces having drawing ordischarge doors at the sides of the hearth.

In the practice of myinvention the furnace as regards the bed 1, withits raised supports 2 2 and the water-cooled bearings 8 for thebillets,may be constructed in accordance with any of the forms known inthe art; but it is preferred to provide for the automatic discharge ofthe billets from the point of highest heat, as set forth in reissuedLetters Patent No. 11,666, granted to me and Joseph Reuleaux on thelstday of May, 1898. This automatic discharge may be effected, as setforth in said Letters Patent, by extending the water-cooled bearings 3with a sharp down inclination, as at 4, from the point of highest heatthrough an opening in the end of the furnace, the portions 4 of thebearings preferably extending over the inletfiue 5. The bearings 3, withtheir extensions 4, form a practically continuous support for thebillets from the charging to the discharging point. ln the constructionshown in Figs. 3 and 4 a slot or opening 6 is formed through the hearth'7 of the furnace, and the bearings 3 extend from the charging end ofthe Vfurnace to this slot or opening,which latter is normally closed bydownwardly-movable doors 6i. A conveyer 8 of any suitable constructionis ar ranged below the hearth in line with the slot or opening fortransferring the heated billets as they drop through the slot and beyondthe doors to the reducing-rolls.

The supports for the bearings 3 may be arranged transversely orlongitudinally of the furnace; but it is preferred to combine both formsof supports, the longitudinal supports 2a being arranged adjacent to thecharging end of the furnace. Transverse supports are preferably employedin the heatingchamber, as the movements of the billets along thebearings will prevent any material accumulation of slag, duc., on thesupports, and the pockets between such supports are readily accessiblefor the removal of the slag, dac. In heating large billets or ingots itis desirable IOO ' supports bynarrow blocks or pillars 14, rest@ ing onthe supports 2 and the bridge-Wall 15, thereby forming longitudinalpassages eX- tending below the bearings 3 and in linev with the passagesformed by the longitudinal supports 2a. lt will be understood that theselongitudinal passages may be formed by cutting away the bridge-wall andsupports 2 at points intermediate of thev bearings.

The roof of the furnace is formed in two or more sections 9 and 10. Thesection 9 is supported by the side and rear walls of the furnace at sucha height above the furnace as will form an effective heating-chamber.

The section 9 of the roof in the direction of its length is given adownward curve or inclination to its point of junction with the section10, while the latter is extended on a straight line approximatelyparallel to the bearings 3. The roof of the furnace at the throat orpoint a of juncture between the sections 9 and 10 is supported at such aheight above the bearings 3 that the billets shifted along said bearingswill barely pass under the roof. The main portionof the section lO maybe a little higher than at the point a; but it is preferred that itshould continue at approximately the same distance from the bearings 3to the charging end or outlet-flues 13 of the furnace. By thus droppingthe front portion of the roof a curtain or baffle wall is formed acrossthe furnace to retard the flow of heat toward the charging end, so thatthe rear or heating chamber can be maintained at a much highertemperature than the front or preheating passage or chamber, and bythe'downward curvature in the roof athorough dissemination of the heatis obtained.

The lengths of the portions of the furnace covered by the two sectionsare so proportioned to the desired rate of-.movement of bil lets throughthe furnace that while. passing through the preheating-chamber thebillets will be heated as high as possible withoutinjurious effects, andwhile passing from the baffle wall or curtain to `the hearth or pointof'discharge'they will be subjected for a sufficient time to the higherheat in the heatingchamberto'raise them to a good rolling temperature.

As shown in Figs. 5 and 6, my improvement Ycan be applied to that formof heating-furnace in which the billets are shifted along thewater-cooled bearings to a hearth 11, from which they are removedthrough side doors 12 by tongs or other suitable means.

lt will be readily understood by those skilled in the art that thefurnaces may be heated by the combustion of'solid fuel in a lire-chamberadjacent to the drawing or discharge end of the furnace, as shown inFigs. 1 to 6,' or by the combustion of gaseous fuel introduced into thefurnace by any of the many means well known in the art.

I claim herein' as my'invention- In a continuous heating-furnace havingbillet-bearings extending longitudinally thereof, and having aheating-chamber adjacent to the drawing or discharge end of the furnaceand a preheating-chamber adjacent to the charging end, a roof formed intwo sections, the section above the heating-'chamber being downwardlycurved in the direction of its length in that portion remote from thepoint of discharge, and the section above the preheating-chamberapproximately parallel to said bearings, and a drop or depressed portioninthe roof intermediate said sections, substantially as set forth.

In testimony whereof' I have hereunto set my hand.

ALEX. LAUGHLIN.

Witnesses:

DARWIN S. WoLco'rT, F. E. GAITHER.

